Plastic containers are used extensively in the packaging industry to contain fluids such as beverages, soaps and oils. These containers are typically formed from polyethylene, polypropylene, polyvinyl chloride, and other flexible plastics. The containers are deformable in that their shape may be changed when a force is applied. When the force is removed, the containers return to their original shape.
Conventional paper labels are not suitable for the plastic containers because such labels cannot expand and contract with the container during hot filling operations or deform during use without wrinkling, tearing, or otherwise damaging the label. Plastic labels made from vinyl or low density polyethylene are available. However, polyvinyl chloride labels are deformable but are not recyclable.
U.S. Pat. No. Re. 32,929 discloses deformable, recyclable labels formed from low and medium density polyethylene. The polyethylene has a density of from about 0.91 g/cm.sup.3 to about 0.94 g/cm.sup.3, preferably from about 0.915 g/cm.sup.3 to about 0.935 g/cm.sup.3. Labels formed from high density polyethylene are also described but are not deformable. When applied to a flexible container, the high density polyethylene label wrinkles, lifts, bubbles and creases when the container is squeezed.
The high density polyethylene labels of the present invention are deformable. The labels can expand and contract with the container during hot filling operations and deform during use without wrinkling, tearing, lifting, bubbling, creasing or otherwise damaging the label. The labels die cut easily because of their low elongation in the transverse direction.
The labels of the present invention have several advantages over low or medium density polyethylene labels. High density polyethylene labels withstand more heat during hot filling operations. The labels can be used with packages that contain oily products without decomposing while low or medium density polyethylene labels would soften and eventually decompose. Furthermore, the labels of the present invention are more compatible for recycling since most of the containers on which the labels are applied are made of higher density materials. The labels are also dispensed automatically at a faster rate than low density polyethylene labels because of their stiffness.